Electrically operated clock with alarm device



May 28, 1963 R. w. REICH 3,091,076

ELECTRICALLY OPERATED CLOCK WITH ALARM DEVICE Filed July 31, 1961 2 Sheets-Sheet 1 40 INVENTOR ROBERT WALTER RE/CH ATTORNEYS May 28, 1963 R. w. REICH 3,091,076

ELECTRICALLY OPERATED CLOCK WITH ALARM DEVICE Filed July 31, 1961 2 Sheets-Sheet 2 H9 5 INVENTOR ROBERT WALTER RE/CH WWW ATTORNEYS United States Patent G 3,091,076 ELECTRICALLY OPERATED CLOCK WETH ALARM DEVICE Robert Walter Reich, Rotackerstrasse 2, Freiburg, Germany Filed July 31, 1961, Ser. No. 128,095 7 Claims. (Cl. 58-38) This application is a continuation-in-part application of my copending application Serial No. 719,812, filed March 7, 1958, now abandoned.

The present invention relates to an electronically operated clock with alarm device.

It is an object of the present invention to provide for a new and improved transistorized clock with alarm device.

It is a feature of the present invention to employ a selfinterruption feed back transistor oscillator to drive a clock via an electromagnetic impelling device energized only by free oscillations of this oscillator.

It is another feature of the present invention to have a rotating contact device drivingly connected to the clock which contact device controls the very weak base current of a transistor being operated in common emitter configuration or circuit connection; the collector circuit of this transistor actuates a sound producing device such as a bell, a sound bar or a record reproducing device.

The objects and features of the invention will become more apparent from the description of the accompanying drawing in which- FIGURE 1 is a circuit diagram and schematic view of an electronic clock drive with alarm device in accordance with the present invention;

FIGURE 2 is a perspective view of an enlarged portion of a cont-act device as shown in FIGURE 1;

FIGURE 3 illustrates the circuit diagram of another embodiment of the present invention;

FIGURES 4 and 5 are respectively front and cross-sectional views of a drum employed in the device shown in FIGURE 3 and taken at lines VV and IVIV, respectively; and

FIGURE 6 is a circuit diagram of another embodiment of the present invention employing a sound reproducing device.

Turning now to the detailed description of the drawing, particularly FIGURE 1 thereof, there is first shown an hour hand 1 and a minute hand 2 rotatably connected to gear wheels 3 and 4, respectively. A gear train or transmission gear designated in general by reference numeral 5 drives these wheels, and train 5 is itself driven by a ratchet wheel 6. A pawl 7 engages ratchet wheel 6. Pawl 7 is disposed on an L-shaped, double arm lever 8, pivoted at its bend by a pivot 9. Arm 10 of lever 3 serves as an armature cooperating with a magnetizable core 11 of a solenoid device 12. Solenoid device 12 has three coils 13', 1 4 and 15, pertaining to an oscillator to be described in the following.

There is first a transistor 16 having its collector-emitter path connected to a voltage source 17, which preferably is a rechargeable battery, or a gas tight accumulator of the miniature type. The electrical connection of transistor 16 to battery 17 is made via coil in the collector circuit, and a resistor 18 in the emitter circuit. Base bias resistor 19 connects the base electrode/of transistor 16 to the plus pole of battery '17.

The feedback control circuit for transistor '16 is comprised of the two other windings 13 and 14 of solenoid 12 serving also as a feedback transformer to establish an oscillator. There is furthermore a relatively speaking small capacitor 20 coupling winding '13 to the base of transistor =16 and thus defining a feedback loop A. A larger capacitor 21 couples winding 14- to this base electrode, thus forming a feedback loop B.

f'ifidldl'iii Patented May 23, 1963 Ratchet wheel 6 also drives another gear wheel arrangement 22 being linked to train 5 and including a contact or switching disc 23. Disc 23 carries contacts 24, and it has a hub 32 electrically connected to all of its contacts 24. There is a stationary sliding contact 33 connected to battery 17. Contacts 2 1 are arranged in groups, and they cooperate with a stationary contact 25. Contact 25 is connected to the base electrode of another transistor 26 via a resistor 27. Transistor 26 is operated in common emitter configuration, and its emittencollector path is also connected to battery 17 via a solenoid coil 28 having a core 29 and a pivoted armature 30. Elements 28 and 29 constitute an electromagnet. Armature 31 serves as electromagnetically agitated clapper of a bell 31.

Turning briefiy to FIGURE 2 there is illustrated an enlarged portion of contact disc 23. This contact disc 23 carries on its circumference twelve sets or groups of contacts which groups are equally spaced from each other and the distance between adjacent groups represents one hour. Disc 23 rotates twice in 24 hours. Basically it is possible to place disc 23 on the same shaft carrying hour hand 1; the separate gearing has been used here primarily for facilitating the illustration.

The twelve contact groups have respectively, one, two, three, etc., up to twelve contacts; the group shown in FIGURE 2 has four of the contacts 24. This group is therefore engaging contact 25' at four oclock. The contacts are sharp blades having a thickness in the range of a thousandth of a millimeter. Also, the distance between the four contacts is about of the same order of magnitude.

tationary contact 25 has a similar sharp edge 25 which is permitted to just engage the blades of contacts 24. All of the contacts, or at least the blades and edges thereof are made of very hard steel so that such mutual engagement does not flatten the edges. Disc 23 rotates very slowly, but the contact time is also to be a very short one. This slow rotation accounts for the edged contacts.

Suppose disc 23 has a diameter of little less than 4 cm. with a circumference of about 12 cm. The circumferential speed of disc 23 which is the speed with which the contacts 24 pass stationary contact 25 is then 12 cm. per hour which speed is 120,000,4/6060 sec.; this amounts to approximately 3Cp/sec. It may be assumed that each contact blade of contacts 24 has a width of about 101/. and there be a distance of 20p between two adjacent contacts. Thus, for each of the four contacts shown in FIGURE 2 there is an actual contact time /3 sec. with a pause of /3 sec. in between; the total time for these four contacts to pass contact 25 is 3 /3 sec.

The device as described thus far operates as follows- Elements 12, 1e, 18, 19, 2t) and 21 constitute an oscillator of the self-quenching type. Coil 13 and capacitor 2%) together with resistor 19 define a feedback loop (dessignated as loop A) of such a gain so as to set up undamped high frequency oscillations preferably in the range of 10 kilo-cycles per second. The loop as defined by coil 14 and capacitor 21 (loop B) superimposes a quenching action which also can be considered as a low frequency modulation with a frequency of one or a few cycles per second. In particular, capacitor 21 periodically positively biases the base of transistor 16 to cut-off so as to interrupt the emitter current. Upon reversal of the charge of capacitor 21, transistor '16 is opened again and permits the production of high frequency oscilla tions. The gain of the loop B including capacitor 21 determines the degree of quenching or, in other words, how many high frequency oscillations are to be produced via the loop A including the capacitor 20.

It has been found suitable to permit the production of a few high frequency oscillations only before the quenchaction suppresses them.

A high gain of the high frequency loop A produces in coil 15 high voltage peaks. Owing to the rectifying effect of transistor 16, the current pulses in coil 15 are unidirectional. The magnetization in core 11 thus produced attracts armature 1t}, and pawl 7 turns ratchet wheel 6 by one step accordingly. The group of pulses in coil 15, produced when the high frequency oscillator is opened, serve in combination and in common action to attract armature it then the quenching prevails, and for a period of time which extends over little less than the oscillation period of the quenching, only negligible and weak pulses appear in coil .15 and armature 18 drops.

It is thus apparent that ratchet wheel 6 is operated with the frequency of the quenching, or of the low frequency modulation which is superimposed upon the high frequency oscillations.

Ratchet wheel 6 drives the gear train which in turn drives hour hand 1, minute hand 2, and contact disc 23.

At any hour, a group of contacts such as 24 approaches contact 25 and a weak current is permitted to fiow over the thin blades opening transistor '26. The coil 28 then energizes core 2E which in turn attracts armature 30 then striking against bell 31. The number of strokes depends precisely on the number of contact blades joined on disc 23 so as to form a group. In case of the group shown in FIGURE 2 there will be four strokes accordingly.

It will be appreciated that disc 23 may also carry contact blades which cause transistor 26 to be activated at quarter, half and three-quarters of an hour. Also, a separate contact diSc-transistor-bell arrangement can be employed to indicate these quarter-fractions of an hour with a tone different from the tone of the hourly produced tone by bell 31.

Proceeding next to FIGURE 3, there is shown a different embodiment of the invention. Reference numeral 40 designates a univibrator having transistors 41 and 42. There is a direct connection line 43 between the collector electrode of transistor 42 and the base electrode of transistor 41, the collector electrode of the latter is connected to the base electrode of transistor 42 via a capacitor 43. The negative pole of a voltage source 44, preferably also a miniature battery or accumulator is connected to the collector electrode of transistor 41 via a winding 46 mounted on a core 47 together with two other windings 48 and 49. Winding 48 connects the plus pole of battery 44 to a capacitor 45 which in turn is connected to the base of transistor 41. Winding 49 directly connects the plus pole of battery 44 to the base electrode of transistor 42; finally, the collector of the latter is connected to the negative pole of battery 44 via an adjustable resistor 50.

A permanent magnet 51 cooperates with the core 49 as will be described below. Magnet 51 is pivotally mounted on a lever 52 pertaining for example to a pawl and ratchet device of the type shown in FIGURE 1. However, magnet 51 may pertain to any kind of driving mechanism as illustrated in FIGURES 2, 6, 7 or 13 of my copending parent application Ser. No. 719,812, filed March 7, 1958. The clock drive is generally designated with reference numerals 53 and it is understood that it includes a gear train or transmission gear and hands similar to those shown in FIGURE 1.

There is a link 54 being a member of such transmission gear, only indicated schematically, which may be comprised of a shaft rotating with the clock mechanism and driving a pinion 55 meshing with a wheel 56 which is mounted on a shaft 57. Shaft 57 is journalled in bearings 58 and 59, but shaft 57 is also capable of moving in axial direction with respect to journals 58 and 59, then serving as guiding elements.

There is an armature 60 in which shaft 57 terminates. Armature 60 is mechanically biased by a spring 61 which is mechanically connected thereto and to stationary bearing member 59.

A solenoid coil 62 is coaxially disposed with respect to armature 60 for attracting the latter against tension of spring 61. The electric current for solenoid coil 62 is also derived from battery 44 via an R-C circuit 75 and a contact 63 actuated by a relay 64 which is connected in the collector circuit of a transistor 65. The base of transistor 65 is connected to and controlled by a resistor 66 and a contact 67 cooperating with contacts on a rotating drum 68; this control action will be explained more fully below.

Drum 68 is mounted on shaft 59 and rotates therewith. There is a line 78 electrically connecting shaft 57 and drum 68 with all of its contacts to battery 44. Another transistor 69 has its base connected to resistor 66 and its collector circuit includes a solenoid or electromagnet 70 having a pivoted armature 71, capable of striking against a suspended sound bar 72. Actuation of solenoid 70 corresponds to that of the bell striking device outlined in connection with FIGURE 1.

The two transistors 65 and 69 are both employed in common emitter configuration.

Turning now for the moment to FIGURES 4 and 5 illustrating enlarged portions of drum 68, there is first disposed a row of contacts 73 along the circumference of drum 68 near that end thereof adjacent to which is disposed stationary contact 67 when shaft 59 is in its normal axial position which normal position is associated to an unenergized state of coil 62.

It will be apparent from FIGURE 4 that during rotation of drum 68 contacts 73 successively engage contact 67. The angular distance of adjacent contacts 73 (angle a) amounts to precisely one-twelfth of its circumference. Thus, upon a completion of one revolution once every twelve hours, contact 67 engages every hour one of the contacts 73 of drum 68. It can be seen that contact 67 is fairly blunt relatively speaking, while contacts 73 have sharp edges. To be more precise, contact 67 has also a sharp edge in a general way, but its edge is broader than that of contacts 73.

Aligned with contacts 73 but disposed in axial direction on the circumference of drum 68 are contacts 74 which are also fairly blunt; they may have an extension taken in direction of the plane of the drawing of FIG- URE 5 which is longer as compared with their width perpendicular thereto.

Each one of the contacts 73 actually defines a row of axially displaced contacts. FIGURE 5 shows three contacts pertaining to the row illustrated. The two neighboring rows disposed below and above the plane of the drawing of FIGURE 5 have respectively two and four contacts. Thus there is altogether a row of one, a row of two, etc. and a row of twelve contacts on the mantle of cylinder or drum 68.

The device illustrated in FIGURES 3, 4 and 5 operates as follows- In its stable state, transistor 42 of univibrator 40 is conductive, and transistor 41 thereof is non-conductive because its base is positively biased to cut-off by its direct connection to the collector of transistor 42.

The iron of armature 47 attracts magnet 51 and the motion of magnet 51 thereby causing a voltage to be induced in the several coils; particularly a negative voltage appears in coil 48 momentarily biasing the base of tran sistor 41 negatively while cutting off the collector bias of transistor 42. Accordingly, the univibrator 40 flips into its unstable state. The current now permitted to flow in coil 46 which is the collector current of presently conductive transistor 41 is amplified considerably by feedback action via coil 48 serving as feedback secondary winding.

This feedback loop defined by coils 46 and 48 and by capacitor 45 sets up a rapid succession of high voltagehigh frequency pulses in coil 46, which pulses constitute oscillations independent from the univibration oscillations. Actually the univibrator serves only as a switch to trigger these pulses. The high current peaks thus flow- '5 ing in coil 46 produce a magnetic field repelling magnet 51.

During the unstable state of univibrator 40, capacitor 45 and resistor 50 define an R-C circuit charging capacitor 45 with DC from the battery 44 which effects again a negative base bias of transistor 41 and a negative col- .lector bias of transistor 42, whereupon the univibrator 'fiips back into the stable state. Magnet 51 becomes attracted again and a new cycle commences.

When resistor 50 is adjusted, the time of instability and of return of the univibrator to its stable state is adjustable accordingly which in turn means that the period of time after which the univibrator flips back into the unstable state for producing another driving pulse is adjustable; in other Words, the time of producing repelling pulses for magnet 51 is adjustable therewith and this determines the sequence of impelling the clock.

The repelling action exerted upon magnet 51 pivots lever 52 which in turn actuates the driving mechanism of the clock 53. Aside from driving the hands of the clock, also pinion 55 and wheel 56 are rotated, in slow steps; and drum 68 follows this rotation. When a contact 73 engages stationary contact 67, transistors 65 and 69 become conductive and a first stroke is produced by armature 71 striking against sound bar 72 when attracted by solenoid 70. .Also, relay 64 closes thus causing coil 62 to slowly pull armature 60 and shaft 57 in the direction of the arrow 77. During such axial motion, contact 67 disengages from contact 73 and it consecutively engages all of the contacts 74 of that row. Relay 64 preferably is one with a delayed release so that disengagement of contact 67 from contact 73 does not produce re-opening of contact 63. However, solenoid 70 is different in that blocking of transistor 69 by the contact disengagement just mentioned releases armature 71 immediately.

It is therefore apparent that drum 68 is pulled in direction of arrow 77 and every time a contact 74 engages contact 67 another stroke is produced by solenoid 70, armature 71, and sound bar 72, also holding action of relay 64 is reinforced.

During the axial motion of drum 68, of course, the rotation thereof continues because pinion 55 remains in engagement with wheel 56.

After contact 67 does not find any more contacts 74 to be engaged with, relay 64 releases delayedly contact 63, and energization of coil 62 is reduced to zero, Armature 60 with shaft 57 and drum 68 are pulled back by spring 61. During this return movement, contact 67 does not engage any of the contacts 73 and 74 because of the continued rotation of drum 68 and, of course, because of the small contact area of contacts 67, 73 and 74. In order to soften any movement, the axial return movement of armature 60 with its connected elements can be carried out slowly in having the capacitor of RC. system 75 discharged also over the resistor thereof or over a different resistor.

Proceeding now to the embodiment shown in FIGURE 6, there is first shown a rotating contact device 80 indicated only schematically and this device can be of any of the contact disc 23 or drum 68 as illustrated in FIGURES 1 to 5. correspondingly, element 81 is a stationary scanner contact cooperating with device 80 such as contacts 25 and 67 (supra). Contact device 80 is connected to a minus pole of a battery via a line 82, and stationary contact 81 is connected to the plus pole thereof via a resistor 83 and the base-emitter path of a transistor 84 having a relay 85 inserted in its collector circuit; the collector circuit is joined to line 82. Transistor 84 is also operated in common emitter configuration.

Relay 85 controls the electric current supply to a DC. motor 86 which drives drum 87 made of magnetizable material and having a magnetic sound track impressed on its circumference. A stationary pick-up coil 88 is provided for picking up this sound track; in other words, upon rotation of drum 87 the permanent magnetization thereon induces in coil 88 a voltage which is used to control a transistor 89 having in its collector circuit connected a loud speaker reproducing the oscillations induced in coil 88 as sound.

The invention is not limited to the embodiments described above, but all changes and modifications thereof not constituting departures from the spirit and scope of the invention are intended to be covered by the following claims.

What is claimed is:

1. An electronic clock comprising: DC. current supply means; a transistor oscillator connected to said current supply means and having a coil as output circuit producing a magnetic field whenever oscillations are produced; a transmission gear driving the clock; means responsive to said magnetic field and driving said transmission means in response thereto; a rotatable contact device linked to said gear for common rotation; a stationary contact cooperating with said rotatable contact device; a transistor in common emitter configuration having its base connected to and controlled via said stationary contact; a magnetizable device connected to and controlled by the collector circuit of said transistor; and sound producing means actuated by said magnetizable device whenever said stationary contact engages a contact of said rotatable contact device. 7

2. An electronic clock comprising: DC. current supply means; a transistor oscillator connected to said current supply means and having a coil as output circuit producing a magnetic field whenever oscillations are produced; a transmission gear driving the clock; means responsive to said magnetic field and driving said transmission means in response thereto; a contact wheel having circumferentially disposed groups of contacts, and being drivingly connected to said gear for common rotation in synchronism with the clock; a stationary contact positioned for successively engaging the contacts of said wheel; a transistor in common emitter configuration having its base connected to and controlled via said stationary contact; a magnetizable device connected to and controlled by the collector circuit of said transistor; and sound producing means actuated by said magnetizable device whenever said stationary contact engages a contact of said rotatable device.

3. An electronic clock comprising: DC. current supply means; a transistor oscillator connected to said current supply means and having a coil as output circuit producing a magnetic field whenever oscillations are produced; a transmission gear driving the clock; means responsive to said magnetic field and driving said transmission means in response thereto; a rotatable contact device linked to said gear for common rotation and including drum having circumferentially disposed groups of contacts, the contacts of each group extending in axial direction; a stationary contact for engaging said contacts; means for axially shifting said drum so that said stationary contact may engage all contacts of one group; a transistor in common emitter configuration having its base connected to and controlled via said stationary contact; a magnetizable device connected to and controlled by the collector circuit of said transistor; and sound producing means actuated by said magnetizable device whenever said stationary contact engages a contact of said rotatable contact device.

4. An electronic clock comprising: DC current supply means; a transistor oscillator connected to said current supply means and having a coil as output producing a magnetic field whenever oscillations are produced; a transmission gear driving the clock; means responsive to said magnetic field and driving said transmission means in response thereto; a rotatable contact device linked to said gear for common rotation; a stationary contact; a transistor in common emitter configuration and having 7 input and output circuits connected to said DC. voltage source, said input circuit connected to said stationary contact; an electromagnet having a coil connected to said output circuit; a bell; and an armature cooperating with said electromagnet for striking said bell.

5. An electronic clock comprising: D.C. current supply means; a transistor oscillator connected to said current supply means and having a coil as output circuit producing a magnetic field whenever oscillations are produced; a transmission gear driving the clock; means responsive to said magnetic field and driving said transmission means in response thereto; a rotatable contact device linked to said gear for common rotation; a stationary contact cooperating with said rotatable contact device; a transistor in common emitter configuration having its base connected to and controlled via said stationary contact; a magnetizable device including a drive connected to and controlled by the collector circuit of said transistor; said drive and a sound reproducing device being driven and actuated by said drive Whenever said stationary contact engages one of said contacts of said rotatable contact device.

6. In an electronic clock having a transmission gear, the combination comprising: a rotatable contact device linked to the transmission gear for common rotation and 25 having circumferentially disposed contacts; stationary contact means for successively engaging said contacts; a transistor having its base connected to said stationary 8 contact; a voltage source having one pole connected to the emitter of said transistor, an electromagnetic device interconnecting the collector of said transistor and the oher pole of said voltage source; and sound producing means actuated by said electromagnetic device.

7. An electronic clock comprising: a rechargeable battery; a self-interrupting electronic oscillator; magnetic irnpelling means controlled by said oscillator; hour and minute hand means driven by said magnetic irnpelling means; a rotatable switching device also driven by said irnpelling means; a stationary contact engaged by said switching device, a transistor in common emitter configuration having its base connected to said stationary contact; and an electromagnetically controlled sound producing device connected to the collector of said transistor.

References Cited in the file of this patent UNITED STATES PATENTS 2,988,708 Schmidt June 13, 1961 FOREIGN PATENTS 1,214,428 France Nov. 9, 1959 OTHER REFERENCES German application 1,060,747, printed July 2, 1959 (K1. 74a4). 

1. AN ELECTRONIC CLOCK COMPRISING: D.C. CURRENT SUPPLY MEANS; A TRANSISTOR OSCILLATOR CONNECTED TO SAID CURRENT SUPPLY MEANS AND HAVING A COIL AS OUTPUT CIRCUIT PRODUCING A MAGNETIC FIELD WHENEVER OSCILLATIONS ARE PRODUCED; A TRANSMISSION GEAR DRIVING THE CLOCK; MEANS RESPONSIVE TO SAID MAGNETIC FIELD AND DRIVING SAID TRANSMISSION MEANS IN RESPONSE THERETO; A ROTATABLE CONTACT DEVICE LINKED TO SAID GEAR FOR COMMON ROTATION; A STATIONARY CONTACT COOPERATING WITH SAID ROTATABLE CONTACT DEVICE; A TRANSISTOR IN COMMON EMITTER CONFIGURATION HAVING ITS BASE CONNECTED TO AND CONTROLLED VIA SAID STATIONARY CONTACT; A MAGNETIZABLE DEVICE CONNECTED TO AND CONTROLLED BY THE COLLECTOR CIRCUIT OF SAID TRANSISTOR; AND SOUND PRODUCING MEANS ACTUATED BY SAID MAGNETIZABLE 